SAH Archipedia uses terms from the Getty Art and Architecture Thesaurus (AAT) to categorize and classify metadata for the entries in the database. For more information on the Getty AAT, click here

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racks (supporting devices)

Frameworks of wire, pegs, bars, gratings, or shelves in or on which articles are placed or suspended, often for storage or stowage; may be freestanding or attached to surfaces.

railroad ties

Strong internal rectangular supports for the rails in railroad tracks.

rails (transit system elements)

Rolled steel bars, commonly T-sections, designed to be laid end to end, usually in pairs and in parallel lines, to provide the running surface for certain transit vehicles.

rammed earth

A material usually consisting of clay, sand, or other aggregate, such as sea shell, and water, which has been compressed and dried; used in building construction.

random ashlar

Building material comprising roughly squared stone blocks of different sizes laid in courses. The horizontal and vertical joints do not line up consistently and smaller stones may be used to fill in gaps.


Synthetic fiber made from regenerated cellulose.

No description is available for this term.

red beech (wood)

Wood of the species Nothofagus fusca, native to cooler regions of the southern hemisphere. It is used in the making of flooring, toys, and tool handles.

red cedar (wood)

General term referring to wood of many evergreen trees of the cypress family.

red fir (wood)

General term for wood from any of many species coniferous trees, including the Scots pine, Fraser fir, Douglas fir, red fir (silvertip fir), and silver fir.

red granite

Granite with a mineral composition that results in a red color and usually a relatively coarse texture.

red gum (wood)

Wood of the species Corymbia calophylla, native to Australia. It is yellowish-red in color, and is used in the manufacture of flooring, paving, and stair treads.

red marble

Marble with a mineral composition resulting in a predominantly red color.

red oak (wood)

In the lumber trade, a general term for wood of many species of oak, including Q. rubra, belonging to a subgroup of oak trees native to North and South America, characterized by having bristle-tipped leaves, acorns with hairy shell linings, and bitter seeds that mature in two seasons. Red oak wood is typically hard, coarse-grained and used commercially for flooring, furniture, cabinets, paneling, and millwork.

red ocher (pigment)

Earth color made from clay or by calcining selected grades of yellow ocher. This type is sometimes called burnt ocher.

red pigment

Pigment having the color red, which is produced by light having a spectrum dominated by energy with a wavelength of about 630–700nm.

red pine (wood, general)

Wood from any of various trees, usually pines or other conifers having reddish bark or wood.

red slate

Slate that has a component of hematite, causing a reddish color.

redwood (wood)

Wood from any of several species of cypress, pine, or cedar having reddish wood.

reflecting pools

Designates artificial areas of water, usually of geometric shape, specifically designed and located so as to mirror buildings or other structures.

reflective glass

Window glass coated on the outside with a transparent metallic coating that reflects light and radiant heat.

reinforced concrete

Concrete that contains embedded reinforcements, typically steel bars, in order to increase strength.

reinforcing bars

Steel bars, usually with manufactured deformations or threading, used in concrete and masonry construction to provide additional strength.

resin (organic material)

General term for solid or semisolid organic substance usually obtained from plant secretions, but sometimes obtained from insects or synthetically produced. It is soluble in organic solvent but not in water, and is commonly used in varnish, printing ink, and size. It is distinguished from "gum" by not being dissoluble in water. To distinguish between natural and synthetic resins, use the narrower terms "natural resin" or "synthetic resin."


Any of a number of extrusive acid igneous rocks, usually porphyritic and exhibiting flow lines, with phenocrysts of quartz and alkali feldspar in a glassy to cryptocrystalline groundmass; the extrusive equivalent of granite.


Layers, facings, or protective embankments comprised of large irregular and randomly placed stones to prevent erosion, scour, or sloughing; also the stone so used.


The land margins of rivers.

riverine bodies of water

Bodies of flowing water moving in one direction, including streams and rivers.


18th-century term for ornamental trimming in the form of bands or stripes on a robe or gown.

rock (inorganic material)

Naturally formed aggregate of one or more minerals. For processed or dressed rock use "stone."

No description is available for this term.

Roman brick

Brick whose nominal dimensions are 2 2/3 x 4 x 12 inches.

Roman tile

A channel-shaped, tapered, single lap, roofing tile.

Romanesque Revival

Refers to the style in European and American architecture dating from the 1820s to the end of the 19th century. Based on the style of the 11th- and 12th-century Romanesque church architecture, it is characterized by semicircular arches, groin and barrel vaults, and the spare use of naturalistic ornament.


Any material used as a roof covering (such as shingles, slate, sheet metal, or tile) to make it wind- and waterproof, and often to provide thermal insulation.

roofing slate

A thin, usually rectangular, piece of certain varieties of slate or other stones which split readily into sheets and are used to cover the roofs of buildings.

roofing tile

Type of tile for roofing, usually of fired clay, concrete, or asbestos cement; available in many configurations and types such as plain tiles, single-lap tiles, and interlocking tiles.


Heavy cord, at least 1/4 inch in diameter, formed by twisting or braiding three to six yarns of natural or artificial fiber. In ancient Egypt, rope was made from reeds or date palm fibers. Ancient rope was also made from flax, grass, esparto grass, hemp, sisal, coir, cotton, jute, papyrus, and camel hair. Up to 1850, most rope was made from hemp or sisal. After this point, abaca and agave became the fibers of choice. By the 1950s, synthetic fibers (nylon, rayon, saran, polyester, etc.) became predominant. Glass and metallic fibers have also been incorporated into rope for added strength and resistance to fire and chemicals.

Rosa Porriiño granite
No description is available for this term.

rose quartz

A pink variety of quartz used as a gemstone.

rosewood (wood)

Wood from several tropical trees of the genus Dalbergia, all having a dark red or purplish color streaked and variegated with black. Rosewood timber produces a rose-like smell when cut. The wood has a fine grain, smooth texture, and polishes to a high gloss, but because of its resinous nature is difficult to work. It is used for cabinets, musical instruments, piano cases, and veneer. It was popular during the late 18th and early 19th centuries. It is still used to fashion xylophone bars, but waning supplies restrict its use. Only around 15 of the species in the large genus Dalbergia yield rosewood.


The solid, brittle, clear resinous residue left after the distillation of turpentine from balsam, having a color ranging from yellow or reddish-brown. It becomes sticky when warm and has a faint pine-like odor. Primarily composed of abietic acid (about 80%), rosin reacts in hot alkaline solutions to form rosin soaps. Rosin weathers poorly, becoming oxidized and brittle with age. It also has poor moisture resistance. Although many of its aging properties are undesirable, rosin is or was used as an ingredient in paints, varnishes, inks, adhesives, sealing wax, soldering fluxes, sizing paper, and linoleum. Because it increases sliding friction, it is commonly used for coating bows of some stringed instruments, and as a slip preventative on the floors of stages and shoes of dancers. The inexpensive resin is also used for sizing paper.


Plaster made of lime mixed with shells or pebbles and used for covering buildings usually by being thrown from a trowel forcibly against a wall.

round barns

Historic barn design that flourished between the late 19th and early 20th centuries in the United States and Canada. Round barns were built in a variety of shapes: octagonal, polygonal, or circular.


Rough, broken stones or bricks. For use in masonry, use "rubblework."

rubble concrete

Form of concrete reinforced by broken stones or brick.


Building material comprising rubble or roughly cut stone.

ruby glass

Glass with a ruby color due to the presence of various materials, including colloidal gold, cadmium selenide, or copper and zinc sulfide.


Strip of lace, cloth, leather, or another material that is gathered on one edge or cut on the bias, so that when attached to the hem, button placard, neckline, or wrist of a garment it produces an ornamental frill or flounce.

running bond

Technique of pattern bond using only stretchers and in which the vertical joints of one course fall midway between the joints of the courses above and below.


Surface pattern originally for stone but frequently simulated in other materials, giving the effect of large blocks with deep, wide joints.